As the speakers at the Desktop Linux Summit 2006 last month looked out at their audiences, they couldn't help but notice that the number of attendees sporting T-shirts, sandals and bushy facial hair -- the stereotypical look of Linux movement die-hards -- was much reduced from previous conferences.

Linux proponents may have grown more buttoned-down, but the open-source operating system is still well outside the mainstream -- at least on desktops. Market research firm IDC expects about nine million PCs running Linux to be shipped worldwide this year, amounting to fewer than five per cent of the total market. And at the desktop conference, messages of hope about Linux's prospects were tempered with criticism of the often-quixotic strategies adopted by Linux proponents and vendors.

One problem is the mistaken belief that open-source equivalents can easily be substituted for widely used Windows applications, said Geoff Perlman, CEO of Real Software. "The mass majority of computer users are conservative," Perlman said. "They want to use the software they're used to using."

Dave Rosenberg, CIO at Glass, Lewis & Co., an investment research and shareholder proxy advisory firm, likewise pointed to the lack of fully functional applications as an issue that's holding back desktop Linux.

Rosenberg, who also works as an analyst at Open Source Development Labs, added that improvements to Linux's hardware drivers and battery life are needed. "My laptop running Ubuntu [Linux] only lasts half an hour," he said. "But these are solvable problems. We're getting there."

Rosenberg argued that Microsoft's upcoming release of its Windows Vista client operating system will prompt many companies to seriously look at switching to Linux on the desktop.

But Rob Enderle, principal analyst at Enderle Group disagreed with that contention. "You can't out-resource Microsoft or out-compete them," he said, noting that PC vendors turn a profit installing Windows on their systems because of all the money Microsoft gives them from its marketing slush fund.

Microsoft also provides plenty of softer incentives to PC vendors, including sales support at large accounts, engineering assistance and help in making the drivers for peripherals work properly.

On the other hand, many PC makers dislike Linux because it doesn't sport a track record of encouraging users to upgrade their computers in regular three-year cycles, as Windows does, Enderle said.

"The PC guys live on churn, and Linux doesn't really change enough for them," he said. "That's theoretically good for IT managers, who would keep employees on the same hardware for nine years if they could. But it's bad for [hardware vendors]."